1. Field of the Invention
The invention relates to a color wheel and more particularly, this invention relates to a color wheel, which is used in projection technology.
2. Description of the Related Art
Digital Light Processing (DLP) is a widely used projection technology. DLP has several advantages, including high brightness, accurate tone reproduction, a fast response time, noise-free operation, and thin, light composition.
In a DLP projector, a digital control method and a reflection principle are adopted. Light rays from the light source are collected and focused by the lenses to pass through three color filters. Then, the light rays are projected onto a digital micro-mirror device (DMD). Since the DMD includes several movable micro mirrors, driving electrodes may control the tilt angle and deflection time of each movable mirror. Then, the light rays are projected to form an image by switching the direction of the light ray reflections.
In the DLP projector, a color wheel 4 for generating the light rays of several colors is generally provided. Herein, the color wheel 4 mainly includes a motor 41, a color filter 42 and a cap 43. The motor 41 includes a housing 411 and a motor body 412, which rotates together with the housing 411. Referring to FIG. 1A, the cap 43 is mounted on the color filter 42, so that the color filter 42 is between the cap 43 and the motor 41. In addition, referring to FIG. 1B, the cap 43 is between the motor 41 and the color filter 42.
Moreover, the color wheel is also used in Liquid Crystal on Silicon (LCOS) projectors and Liquid Crystal Display (LCD) projectors. Herein, the function of the color wheel is the same as in DLP projectors for separating the light rays into several colors.
In general, the motor for the color wheel rotates at a speed higher than 7200 rpm. When the rotation center of the color filter is away from the central axis of the rotation shaft (i.e., when the rotation center is not located on the central axis of the rotation shaft), or friction between the color filter and the air is produced, the color filter may be adversely influenced by vibration. Furthermore, the color wheel may also be adversely influenced by noise (volume is about 58 dBA, detect far from 4 cm).
Currently, the development of the projection system goes toward minimization and portability, so the quality of the product is deeply influenced by noise.
It is therefore an important objective of the invention to provide a color wheel to solve the problem mentioned above.
An objective of the invention is to provide a color wheel, which may have the advantages of solving the vibration problems of the color filter.
To achieve the above-mentioned objective, the invention provides a color wheel including a motor, a vibration damping element and a color filter. In this case, the motor has a housing and a motor body and the housing is set at the central axis of the motor body. The vibration damping element is set on the housing of the motor. The color filter is set on the housing of the motor, so that the vibration damping element is positioned between the motor and the color filter. In addition, the invention also provides other two color wheels.
As mentioned above, the invention provides a color wheel, in which a vibration damping element or a vibration damping material is used. Compared to the prior art, the vibration of the color filter may be reduced in this invention. Furthermore, since the vibration of the color filter may be reduced, noise produced by the vibration may also be reduced. Moreover, the quality of the color wheel may also be improved. In addition, when the cap is made of a vibration damping material, not only the cap may enlarge the contact area between the color filter and the motor, but also the vibration and noise caused by the color filter is further reduced.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.